JP 2013-29127A (Reference 1) discloses a refrigerant control valve device (a valve device in Reference 1) in which a valve body is rotatably accommodated in a valve housing, and the refrigerant control valve device includes a ring-shaped seal body (a seal member in Reference 1), which is inserted from the outside into a cylindrical portion of a guide member that constitutes a refrigerant flow path, and a spring member which biases the seal body in a direction where the seal body comes into contact with the outer surface of the valve body. Here, the valve body has a spherical outer surface, and the seal body is formed in a ring shape so as to come into contact with the outer surface. A communication portion is formed on the outer circumferential surface of the seal body so as to apply the pressure of the refrigerant to a pressure receiving surface of the seal body facing a valve body, and a pressure receiving surface opposite to the pressure receiving surface. In addition, by making the respective pressure receiving surfaces have the same area and forming the communication portion, the pressure applied to the pressure receiving surface from the refrigerant in a direction opposite to the biasing force of the spring member and the pressure applied to the pressure receiving surface from the refrigerant in a direction along the biasing force of the spring member cancel out each other, thereby inhibiting a trouble that a pressure is excessively applied to the seal body.
In the refrigerant control valve device in Reference 1, a predetermined pressure is applied to the pair of pressure receiving surfaces from the refrigerant when the valve body is in an opened posture. However, because the refrigerant is not supplied into the space in which the valve body is accommodated when the valve body is in a closed posture, there is concern that the pressure applied to the pair of pressure receiving surfaces from the refrigerant may be temporarily unbalanced when the valve body is operated.
In a case in which the pressure applied to the pair of pressure receiving surfaces of the seal mechanism is unbalanced as described above, the contact pressure of the seal body to the valve body is also changed, and as a result, there is concern that a sealing property may be deteriorated.
Thus, a need exists for a refrigerant control valve device which is not susceptible to the drawback mentioned above.